Hello, syzbot found the following issue on: HEAD commit: 534293368afa Merge tag 'kbuild-fixes-v6.3' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12247281c80000 kernel config: https://syzkaller.appspot.com/x/.config?x=e23c4bcf73cdc669 dashboard link: https://syzkaller.appspot.com/bug?extid=b8e6e6822d493a4630f3 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b8e6e6822d493a4630f3@xxxxxxxxxxxxxxxxxxxxxxxxx EXT4-fs (loop2): 1 truncate cleaned up EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: writeback. ====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc2-syzkaller-00387-g534293368afa #0 Not tainted ------------------------------------------------------ syz-executor.2/1999 is trying to acquire lock: ffff888029121ee0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline] ffff888029121ee0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_inline_data_truncate+0x1a8/0xd70 fs/ext4/inline.c:1932 but task is already holding lock: ffff88801ae60650 (sb_internal){.+.+}-{0:0}, at: evict+0x2ed/0x6b0 fs/inode.c:665 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_internal){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1477 [inline] sb_start_intwrite include/linux/fs.h:1599 [inline] ext4_evict_inode+0x114b/0x1ca0 fs/ext4/inode.c:240 evict+0x2ed/0x6b0 fs/inode.c:665 iput_final fs/inode.c:1748 [inline] iput.part.0+0x50a/0x740 fs/inode.c:1774 iput+0x5c/0x80 fs/inode.c:1764 dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401 __dentry_kill+0x3c0/0x640 fs/dcache.c:607 shrink_dentry_list+0x12c/0x4f0 fs/dcache.c:1201 prune_dcache_sb+0xeb/0x150 fs/dcache.c:1282 super_cache_scan+0x33a/0x590 fs/super.c:104 do_shrink_slab+0x428/0xaa0 mm/vmscan.c:853 shrink_slab_memcg mm/vmscan.c:922 [inline] shrink_slab+0x388/0x660 mm/vmscan.c:1001 shrink_one+0x502/0x810 mm/vmscan.c:5343 shrink_many mm/vmscan.c:5394 [inline] lru_gen_shrink_node mm/vmscan.c:5511 [inline] shrink_node+0x2064/0x35f0 mm/vmscan.c:6459 kswapd_shrink_node mm/vmscan.c:7262 [inline] balance_pgdat+0xa02/0x1ac0 mm/vmscan.c:7452 kswapd+0x677/0xd60 mm/vmscan.c:7712 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #1 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire mm/page_alloc.c:4716 [inline] fs_reclaim_acquire+0x11d/0x160 mm/page_alloc.c:4730 might_alloc include/linux/sched/mm.h:271 [inline] slab_pre_alloc_hook mm/slab.h:728 [inline] slab_alloc_node mm/slub.c:3434 [inline] __kmem_cache_alloc_node+0x41/0x320 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:966 [inline] __kmalloc_node+0x51/0x1a0 mm/slab_common.c:974 kmalloc_node include/linux/slab.h:610 [inline] kvmalloc_node+0xa2/0x1a0 mm/util.c:603 kvmalloc include/linux/slab.h:737 [inline] ext4_xattr_inode_cache_find fs/ext4/xattr.c:1552 [inline] ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1595 [inline] ext4_xattr_set_entry+0x1d82/0x39e0 fs/ext4/xattr.c:1737 ext4_xattr_block_set+0x618/0x3030 fs/ext4/xattr.c:1974 ext4_xattr_move_to_block fs/ext4/xattr.c:2668 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2743 [inline] ext4_expand_extra_isize_ea+0xa84/0x1880 fs/ext4/xattr.c:2835 __ext4_expand_extra_isize+0x33e/0x470 fs/ext4/inode.c:5960 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6003 [inline] __ext4_mark_inode_dirty+0x51b/0x800 fs/ext4/inode.c:6081 __ext4_unlink+0x667/0xcd0 fs/ext4/namei.c:3269 ext4_unlink+0x41f/0x590 fs/ext4/namei.c:3298 vfs_unlink+0x355/0x930 fs/namei.c:4250 do_unlinkat+0x3df/0x670 fs/namei.c:4316 __do_sys_unlinkat fs/namei.c:4359 [inline] __se_sys_unlinkat fs/namei.c:4352 [inline] __ia32_sys_unlinkat+0xc1/0x130 fs/namei.c:4352 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 -> #0 (&ei->xattr_sem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 down_write+0x92/0x200 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline] ext4_inline_data_truncate+0x1a8/0xd70 fs/ext4/inline.c:1932 ext4_truncate+0x992/0x1340 fs/ext4/inode.c:4298 ext4_evict_inode+0xb9f/0x1ca0 fs/ext4/inode.c:286 evict+0x2ed/0x6b0 fs/inode.c:665 iput_final fs/inode.c:1748 [inline] iput.part.0+0x50a/0x740 fs/inode.c:1774 iput+0x5c/0x80 fs/inode.c:1764 do_unlinkat+0x42e/0x670 fs/namei.c:4323 __do_sys_unlinkat fs/namei.c:4359 [inline] __se_sys_unlinkat fs/namei.c:4352 [inline] __ia32_sys_unlinkat+0xc1/0x130 fs/namei.c:4352 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 other info that might help us debug this: Chain exists of: &ei->xattr_sem --> fs_reclaim --> sb_internal Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_internal); lock(fs_reclaim); lock(sb_internal); lock(&ei->xattr_sem); *** DEADLOCK *** 2 locks held by syz-executor.2/1999: #0: ffff88801ae60460 (sb_writers#4){.+.+}-{0:0}, at: do_unlinkat+0x18c/0x670 fs/namei.c:4297 #1: ffff88801ae60650 (sb_internal){.+.+}-{0:0}, at: evict+0x2ed/0x6b0 fs/inode.c:665 stack backtrace: CPU: 0 PID: 1999 Comm: syz-executor.2 Not tainted 6.3.0-rc2-syzkaller-00387-g534293368afa #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 down_write+0x92/0x200 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline] ext4_inline_data_truncate+0x1a8/0xd70 fs/ext4/inline.c:1932 ext4_truncate+0x992/0x1340 fs/ext4/inode.c:4298 ext4_evict_inode+0xb9f/0x1ca0 fs/ext4/inode.c:286 evict+0x2ed/0x6b0 fs/inode.c:665 iput_final fs/inode.c:1748 [inline] iput.part.0+0x50a/0x740 fs/inode.c:1774 iput+0x5c/0x80 fs/inode.c:1764 do_unlinkat+0x42e/0x670 fs/namei.c:4323 __do_sys_unlinkat fs/namei.c:4359 [inline] __se_sys_unlinkat fs/namei.c:4352 [inline] __ia32_sys_unlinkat+0xc1/0x130 fs/namei.c:4352 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf7fcf579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f7fca5cc EFLAGS: 00000296 ORIG_RAX: 000000000000012d RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000200003c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 retq 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
